On the basis of experimental dependencies of the nonfreezing interlayer thickness H on the external pressure P, isotherms of disjoining pressure of the interlayers II(H) are calculated. The isotherms obey exponential form, like in the case of structural repulsion of hydrophilic surfaces in water at room temperature. Such form of the II(H) isotherm should result in logarithmical dependence of the thickness of nonfreezing interlayers on temperature. An analysis of the experimental data has shown that the H(ln Delta T) dependence consists in two linear parts corresponding to the isotherm with two decay lengths : lambda(1) = 2.5 nm at H < 7 nm and lambda(2) = 17 nm at H > 7 nm. In the case of nonfreezing interlayers, the short-range term is rather caused by roughnesses of ice surface, The long-range term may be connected with the structural repulsion forces acting between hydrophilic surfaces of ice and silica.